Major feature additions

* Customizable time stamps
* Splitting up logging into separate files (info, warn, stop)
* Customizable suffixes for separate log files

TODO: allow for more flexible file names. Currently the user is expected
      to provide a file name without extension that is then used to
      generate all actual file names for the log files.
      Ideally, a user could submit any kind of file that is than parsed
      via regexs to generate the final file names.